Pile changer



Feb.'1, 1955 M. SCHMIDT EI'AL 2,701,136

- PILE CHANGER Filed April 22, 1950 5 Sheets-Sheet 1 INVENTO S Feb. 1, 1955 M. SCHMIDT EI'AL 2,701,136

FILE CHANGER Filed April 22, 1950 5 Sheets-Sheet 3 l l l .9 71* i I I I l ul .m uLf FIG. 3 I INVENTOR6 Mam-01v Scan/a7 Feb. 1, 1955 SCHMIDT ETAL 2,701,136

I FILE CHANGER Filed April 22, 1950 5 Sheets-Sheet 4 .92 gf 9.9 0 7,706 f 10a" 2 14 6 3 I 336 i 7 7 9 n l I V INVENTORS Mo ra Scan/or Feb. 1, 1955 M. SCHMIDT ET AL PILE CHANGER 5 Sheets-Sheet 5 Filed April 22. 1950 I v r v United States Patent PILE CHANGER Morton Schmidt, Redwood City, and Leonard F. Raynaud, San Francisco, Calif., assignors to Schmidt Lithograph Company, San Francisco, Calif., a corporation of California Application April 22, 1950, Serial No. 157,592

12 Claims. (Cl. 271-62) This invention relates to improvements in pile changers, that is means for replenishing a supply of sheets from the top of which sheets are taken one by one and fed to a printing or other sheet handling machine.

When a given printing job calls for a quantity of sheets in excess of the pile that may be supported on the elevating mechanism of the machine it is desirable to eliminate approximately or completely the time interval consumed in shifting from a depleted pile to a new full pile, in other words to make the feeding operation continuous or substantially so. Not only does this save the time of an expensive machine, but an interruption in the printing operation tends to build up ink on the inking rolls and to cause the first sheets printed after resumption of operation to receive too much ink or the printing to be uneven from one end of the sheet to the other.

In accordance with the present invention each pile is built up upon a pallet. The pile is elevated gradually in a conventional manner to maintain the top of the pile at substantially a constant level. When the pile is depleted an auxiliary pile support is manipulated to take and support the pallet without interfering with the feeding of the sheets. This auxiliary support has its own elevating mechanism which may be controlled by the height gauge that normally controls the elevating mechanism of the main pile support. A new full pile is then brought into position underneath the auxiliary pile support and raised until it contacts or substantially contacts the lower surface of the pallet then carried by the auxiliary pile support. Thereupon the latter pallet may be withdrawn, thereby depositing the few remaining sheets of the depleted pile on the top of the new pile, after which the operator throws off the elevating mechanism for the auxiliary pile and throws on the elevating mechanism for the main pile. The feeding of sheets thereafter continues until the new pile nears depletion, when the same procedure may be repeated.

One of the objects of the invention therefore is the provision in apparatus of this kind of means for changing piles without substantial interruption of the feeding operation.

Another object is the provision of an auxiliary pile support of novel construction and mounting.

Still another object is the provision of novel means for controlling the elevating mechanisms of the main and auxiliary pile supports which shall be responsive to the movements of a single height gauge.

A further object is the provision of hanger means for the auxiliary pile support which shall provide a rigid non-swaying mounting for the pallet which mounting shall be readily movable into and out of operative position and which shall be adjustable to accommodate pallets of different dimensions.

Other objects and advantages will appear as we proceed with the description of that embodiment of the invention which, for the purposes of the present application, we have illustrated in the accompanying drawings, in which Fig. 1 is an elevational view of the pile support and elevating means viewed from the rear end of the feeder.

Fig. 2 is a plan view of the same.

Fig. 3 is a side elevational view looking in the direction of arrow A of Figs. 1 and 2.

Figs. 4 and 5 are detail sectional views taken substantially on the lines 4-4 and 55 of Fig. 2.

Fig. 6 is a partially diagrammatic detail elevational view on a larger scale illustrating a portion of the control means for the elevating mechanism of the main and auxiliary piles.

Fig. 7 is an elevational view of the same looking in the direction of arrow B of Fig. 6.

Fig. 8 is a fragmental plan view on a larger scale illustrating some of the controls for the pile elevating mechanisms, and

Fig. 9 is a fragmental detail elevational view looking in the direction of arrows 99 of Fig. 8 and illustrating the means for moving the height gauge up and down in timed relation with the feeder cycle.

In the drawings there is illustrated a feeder frame comprising uprights 10 and 11 and overhead frame members 12. Each of the overhead members 12 carries a pair of sheaves 13 and 14 over which run cables 15 and 16. Each of the two cables 15 extends from sheave 13 directly to a winding drum 17, of which there are two, while each of the cables 16 runs from its sheave 14 over a second sheave 18 and thence down to one of the drums 17. The lower ends of these four cables are secured to stirrups 19 which may be slipped over the flat ends of Lbeams 20 which together constitute the carriers for the main pile support.

The latter support may be in the form of a skid which comprises four legs 21 that are attached in pairs to heavy planks 22 that are secured to transverse bars or other platform material 23. On top of the skid we place a relatively light weight pallet 24 upon which the sheets S are piled. Pallet 24 extends rearwardly of the pile as shown in Figs. 2 and 3. Hand holes 25 may be formed in this rearward extension.

Turning with each of the two drums 17 there is a worm wheel 26 which meshes with one of a pair of worms 27 that are fixed to a shaft 28 journaled in the frame of the machine. This shaft may be turned continuously in either direction by conventional means to operate the drums 17 for lowering or raising the I-beams 20, or it may be turned intermittently in one direction for elevating the I-beams an increment at a time by means which will presently be described.

Four brackets 30 are mounted upon and extend upwardly from the overhead frame members 12. In these brackets four vertical shafts 31 are rotatably mounted. The lower portions of these shafts are threaded as appears in Fig. 3. On their upper ends are bevel gears 32. The brackets 30 also carry bearings for two shafts 33 upon which are fixed bevel gears 34 that mesh with the bevel gears 32. On the forward ends of shafts 33 there are bevel gears 35 which mesh with bevel gears 36 on a transverse shaft 37 at one end of which there is a worm wheel 38 that is driven by a worm 39 which is keyed to the shaft of a small electric motor 40 supported upon one of the overhead frame members 12.

As a part of the auxiliary pile support we provide a pair of transverse rails 41, each of which comprises two spaced bars 42 set on edge, Figs. 4 and 5. These rails extend into the brackets 30 where they carry nuts 43 which receive the threaded parts of the shafts 31. Consequently when the screw shafts 31 are turned in one direction or the other the rails are raised or lowered. The operation is uniform throughout since the screw shafts are identical and are driven at the same rate of speed. Spaced inwardly somewhat from the ends of the rails, racks 45 are positioned between the bars 42 and rigidly secured thereto by machine screws, spot welds, or otherwise, care being taken to position the racks accurately so that the teeth in the two racks at each side of the machine shall be aligned.

Longitudinal shafts 46 have pinions 47 keyed thereto, which pinions mesh with the racks 45. Each of these shafts carries inwardly of the pinions 47 rollers 48 which run upon the inner bar 42 of each rail to take the load of the shafts and the parts supported thereby including a depleted pile of sheets. Depending from each of the shafts 46 are two hangers 49 which are metal straps that are mounted upon the shafts by means of pillow blocks 50 that aer bolted to the straps. Preferably the upper ends of each pair of straps are rigidly interconnected by a bar 51 which is secured at its ends to the upper ends of the straps.

In order to prevent the hangers from swaying on the shafts 46, a horizontal bar 52 is set into a recess in each strap 49 and secured thereto as by welding, and this bar carries near its ends studs upon which are journaled rollers 53 that bear against the under surface of one of the rail bars 42, see particularly Fig. l of the drawings.

Welded or otherwise secured to the lower ends of each pair of straps 49 there is an angle bar 54 constituting a track. These tracks are adapted to receive the side edges of a pallet 24, that is the edge that projects laterally beyond the pile of sheets which lie upon it. The under surface of the pallet may be provided with thin sheet metal strips 55 which bear against the tracks and serve to minimize friction when the pallet is slid rearwardly off the tracks for the purpose presently to be described.

The two hangers carrying the tracks 54 are interconnected for simultaneous operation to move the hangers inwardly or outwardly as indicated by the full and dotted line positions of Fig. 1. Means for accomplishing this purpose may comprise rods 57 and 58 attached at their outer ends to the hangers and having racks 59 and 60 at their inner ends which engage and mesh with the upper and lower sides of a pinion 61 that is fixed upon a shaft 62 which is mounted at its forward end in a bearing 63 cartied in the forward rail 41 and at a point adjacent the pinion in a bearing forming part of a housing 64 carried by the rear rail 41 which also houses the pinion 61 and the racks 59 and 60. The shaft extends rearwardly beyond this rail to a point convenient for manual operation where it carries a hand wheel 65 by means of which it may be turned in either direction.

When the rods 57 and 58 are pulled inwardly this pull is transmitted to the two rear straps 49 and thence to the shafts 46, and because the pinions 47 are keyed to these shafts the pinions travel along the racks 45 and maintain parallel the two shafts 46 and the tracks 54 depending therefrom.

The elevating mechanism for the main pile support is mechanical. It comprises a pair of drums 17 previously described. On the shaft 28 which carries the two Worms 27 there is keyed a ratchet wheel 65. The pawl 66 cooperating with the ratchet is pivoted on one end of a lever 67 that is mounted to oscillate upon the shaft 28, being operated by a link 68 connected at one end to the lower end of the lever and at the other end to a crank 69 on a disk 70 which turns once for each sheet fed. Pawl 66 carries a roller 71 which is adapted to run upon a curved track 72 which forms part of a masking lever 73 that is pivoted to the frame at 74. Obviously when the lever 73 is swung down somewhat the pawl 66 will advance the ratchet 65 one step for each oscillation of the lever 67, but when the lever 73 is raised to the extent illustrated in Fig. 6 the roller 71 merely rides back and forth on the masking track 72 and the ratchet remains stationary.

Referring now to Figs. 8 and 9, there is disposed above the rearward edge of the pile of sheets S a height gauge 76. This gauge is threadably mounted in a rocker arm 77 that is mounted on a fixed pivot 78. The arm is rocked up and down by cam 79 which is given one turn for each cycle of the feeder. This cam permits a swing of the arm 77 through a certain predetermined angle, but the maximum angle of swing is accomplished only when the height of pile S does not interfere with and limit the downward motion of the gauge 76. The swing of arm 77 is communicated to a rock shaft 80 by a link and crank 81 and 82. Shaft 80 runs crosswise to one side of the machine where it communicates its motion to a longitudinal shaft 83 by means of a pair of bevel gears 84 and 85. At its forward end shaft 83 carries a crank 86 which is connected by means of a link 87 with one arm 88 of a bell crank lever, the other arm 89 of which carries two adjustable screws 90 and 91. The bracket upon which the bell crank lever 88, 89 is pivoted has a fixed arm 92 upon which is pivoted a latch 93 having a horizontal arm that is adapted to be engaged by screw 90. The latch is biased to the Fig. 7 position by means of a small spring 94. At its lower end it has a beveled projection 95 that is adapted to engage a pin 96 on a vertical rod 97 which is attached at its lower end to a noddle pin 98 on lever 73 and it its upper end is provided with a slot 99 in which is received a pin 100 on the arm 89 of the bell crank. It will be apparent therefore that when the shaft 83 rocks far enough in a counterclockwise direction as viewed in Fig. 7, screw will retract latch 93, permitting rod 97 and lever 73 to move downward by gravity with the result that pawl 66 is permitted to engage ratchet 65 and advance it one step due to the oscillation of lever 67. When the rock shaft 83 moves back in response to the upward swing of height gauge arm 77, spring 94 is permitted to function and as the pin reaches the upper end of slot 99 it pulls the rod 97 upward causing pin 96 to cam the latch 93 over until it can engage beneath the pin and hold the rod in raised position so that the next oscillation of pawl 66 will be ineffective. When the elevating mechanism for the main pile support is to be disabled, as when the depleted pile is taken by the auxiliary pile support, the operator locks up the rod 97 by any suitable means, the means illustrated in Fig. 6 being a disk 101 eccentrically mounted at 102 and turned by a hand crank 103 to engage beneath a laterally extending projection 104 on rod 97. At such times the latch 93 will be retracted intermittently but it will have no effect upon the rod 97.

The elevation of the auxiliary pile support, as previously stated, is effected by the small electric motor 40. The control is such that the circuit for the motor is closed momentarily only and the rotation of the motor shaft while the current is on plus the coasting of the motor rotor thereafter is sufficient to raise the pile support appreciably. The motor circuit is indicated diagrammatically in Fig. 6. It comprises a switch 105 operated by a push button 106 which is in the path of screw 91. The circuit from line wires 107 and 108 also includes a hand switch 109 which is normally open but is closed when the control for the motor is to be employed, that is when the feed of sheets is taking place from the depleted pile carried by the auxiliary support. It will be apparent that when the level of the pile descends sufiiciently the height gauge travel will cause shaft 83 to rock counterclockwise sufficiently to lower bell crank arm 89 far enough to close switch 105 for an instant, which will result in a short operation of motor 40 to raise the level of the pile. The succeeding oscillations of the height gauge being through a lessened angle will not operate switch 105 until the height of the pile descends far enough to cause the push button 106 to be depressed.

The details of the sheet separating and feeding means form no part of the present invention and will therefore be described very briefly. The feeder shown is a stream feeder which operates from the rear of the pile. It comprises a pair of combing wheels 110 which comb the sheets at the top of the pile against presser feet 111. 112 are sheet separating and lifting suckers which raise the uppermost sheet to the level of forwarding suckers 113 by which the sheet is taken and controlled while it is floated forwardly on forwardly directed air blasts. This causes the forward end of the sheet to move 00. the pile onto moving tapes 114 and beneath pull out wheels 115.

0pcrati0n.ln making up a pile a pallet 24 is placed upon a skid 21, 22, 23 and the sheets are piled on the pallet. When the pile reaches the proper height a lift truck is inserted beneath the skid and the truck is moved into position within the frame of the machine. The I-beams 20 are then placed under the skid and the stirrups 19 are slipped over the ends of the I-beams, after which the drums 17 are operated to raise the skid off the lift truck and elevate it so that the top of the pile shall be at approximately the desired height. The operator then makes sure that switch 109 is open and that the eccentric disk 101 is lowered. The feeder is then started, causing the disk 70 and the cam 79 to rotate in timed relation with the feeder cycle. The elevation of the pile then proceeds an increment at a time. At this time the hanger straps 49 are in the retracted position shown in dotted lines in Fig. 1. When the pile has been depleted to such an extent that the pallet is at a level just above the horizontal parts of tracks 54 the operator turns wheel 65 to bring the hangers into the full line position of Fig. 1, after which he throws the disk 101 over to lock the rod 97 in raised position and closes switch 109. The feed of sheets then continues from the depleted pile. The operator now lowers the cables 15 and 16 and the I-beams 20 and wheels a new full pile into position, attaches it to the lifting cables and operates the elevating means to bring the top of the new pile substantially up to the lower surface of the pallet on which the depleted pile rests. He then grasps the pallet by the hand holes 25 and slides it out from under the depleted pile, permitting the latter to fall and rest upon the new full pile. He then shifts the control back to the mechanical elevating means by turning the disk 101 to the illustrated position and opening the switch 109. Immediately after the depleted pile is lowered onto the main pile the top sheet will be somewhat lower than normal, but this is quickly overcome by the intermittent elevating means which will operate at every cycle until the difliculty is overcome.

The motor 40 is reversible and may be operated continuously in either direction by suitable controls not herein shown for raising or lowering the auxiliary pile support preparatory to starting the intermittent elevation of the same. As a precautionary measure limit switches 120 and 121, Fig. 3, are provided to interrupt current to the motor whenever a horizontal arm 122 moving with the rear rail 41 contacts one of these switches.

Having thus described our invention, we claim:

1. In a sheet feeder, a feeder frame, sheet separating means, a main pile support, a pallet on said support adapted to receive a pile of sheets, means mounted on said frame for elevating said main support, an auxiliary pile support carried by said frame above the level of said sheet separating means, hangers depending from said auxiliary support projecting downwardly below the level of said sheet separating means adapted to engage the pallet of a depleted pile, means carried by said auxiliary support for moving said hangers jointly inward and outward toward and away from said pallet, and means carried by said frame above the level of said sheet separating means for elevating said auxiliary support an increment at a time, whereby sheets may be fed from said auxiliary support while a new pile is being brought up beneath the pallet and whereby said pallet may be withdrawn and said depleted pile deposited upon the new pile.

2. In a sheet feeder, a feeder frame, sheet separating means, a main pile support, a pallet on said support adapted to receive a pile of sheets, means mounted on said frame for elevating said main support, an auxiliary pile support carried by said frame above the level of said sheet separating means, hangers depending from said auxiliary support projecting downwardly below the level of said sheet separating means adapted to engage the pallet of a depleted pile, said auxiliary support comprising a pair of parallel rails disposed transversely of the direction of feed and a pair of spaced shafts supported by said rails upon which said hangers are mounted, and common means carried by said rails and asso ciatcd with said shafts for moving the pallet engaging portions of the hangers toward or away from each other, and means carried by said frame above the level of said sheet separating means for elevating said auxiliary support an increment at a time, whereby sheets may be fed from said auxiliary support while a new pile is being brought up beneath the pallet and whereby said pallet may be withdrawn and said depleted pile deposited upon the new pile.

3. In mechanism of the character described, a feeder frame, sheet separating means, a main pile support, a pallet on said support adapted to receive a pile of sheets, means mounted on said frame for elevating said main support, an auxiliary pile support, vertical screws mounted upon said frame above the level of said sheet separating means, nuts on said auxiliary support receiving said screws, driving means for turning said screws simultaneously, hangers depending from said auxiliary support projecting downwardly below the level of said separating means adapted to engage beneath said pallet when the pile has been depleted, means carried by said auxiliary support for moving said hangers jointly inward and outward toward and away from said pallet, and automatically acting means responsive to pile height for operating said screws to raise the depleted pile an increment at a time, whereby said pallet may be withdrawn and said depleted pile deposited upon a new pile brought up beneath it by said first named elevating means.

4. In mechanism of the character described, a feeder frame, sheet separating means, a main pile support, a pallet on said support adapted to receive a pile of sheets, means mounted on said frame for elevating said main support, an auxiliary pile support mounted on said frame above the level of said sheet separating means, hangers depending from said auxiliary support projecting downwardly below the level of said sheet separating means adapted to engage beneath said pallet when the pile has been depleted, means carried by said frame above the level of said sheet separating means for elevating said auxiliary support an increment at a time, said auxiliary support comprising two spaced parallel rails in which said nuts are mounted, means carried by said rails for moving said hangers inward and outward toward and away from said pallet, means carried by and movable with the hangers engaging said rails at points spaced oppositely from the hangers for preventing swinging movement of the hangers, and automatically acting means responsive to pile height for operating the elevating means of said auxiliary support an increment at a time, whereby said pallet may be withdrawn and said depleted pile deposited upon a new pile brought up beneath it by said first named elevating means.

5. In mechanism of the character described, a feeder frame comprising overhead members, a main pile support, means for feeding sheets from the top of said pile, a pallet on said support adapted to receive a pile of sheets, means for elevating said support, an auxiliary pile support comprising four brackets mounted upon and extending upwardly from said overhead members, a vertical screw in each of said brackets, a pair of parallel rails, nuts on said rails receiving said screws, driving means for turning all of said screws simultaneously for raising or lowering said rails, two shafts disposed at right angles to said rails and supported thereby, hangers depending from said shafts adapted to engage said pallet when the pile of sheets thereon has been depleted, and common means associated with said shafts for moving the hangers toward or away from each other.

6. In mechanism of the character described, an auxiliary pile support comprising a pair of parallel rails, racks mounted in said rails, means for raising and lowering said support, two shafts disposed at right angles to said rails, having pinions fixed thereto and running on said racks, hangers depending from said shafts adapted to engage a pallet, and common means for moving said shafts toward each other, whereby said hangers may be moved parallel to each other into supporting engagement with a pallet.

7. Mechanism as defined in claim 5, wherein the hangers mounted on said shafts comprise tracks parallel to the shafts for slidably supporting said pallet, whereby said pallet may be withdrawn and said depleted pile deposited upon a new pile brought up beneath it by said main pile support.

8. In mechanism of the character described, a main pile support, an auxiliary pile support to which a depleted pile may be transferred from said main support, means for elevating said main pile support an increment at a time, electric motor driven means for elevating said auxiliary pile support an increment at a time, a height gauge adapted to contact the top of a pile on either one of said supports, control means responsive to a predetermined downward movement of said height gauge for setting in motion momentarily the elevating means of said main support, and control means responsive to a like predetermined movement of said height gauge for setting in motion momentarily the elevating means of said auxiliary support, the control means for setting in motion said last named elevating means comprising a switch in the circuit of said motor that is closed momentarily when the said height gauge moves downward to the said predetermined extent.

9. Mechanism as defined in claim 8, wherein the elevating means for said main support is mechanical, a latch for normally holding said mechanical means in inoperative condition, a swinging arm which is adapted to withdraw said latch and close said switch momentarily, and means operatively connecting said arm with said height gauge.

In mechanism of the character described for use in connection with a sheet feeder, a main pile support, an auxiliary pile support to which a depleted pile may be transferred from said main pile support, mechanical means for elevating said main pile support, control means comprising a latch biased to hold said mechanical means out of operation, an electric motor for elevating said auxiliary pile support, a normally open switch in the circuit of said motor, a height gauge disposed above the top of a pile carried by either of said pile supports, means in timed relation with the cycle of said feeder for moving said height gauge up and down, a lever operatively connected with said height gauge to swing through an arc which varies with the extent of movement of the gauge, and means carried by said lever for withdrawing said latch and for closing said switch momentarily when the lever moves through an arc of more than a predetermined angle.

11. Mechanism as defined in claim 10, comprising means under the control of the operator for disabling either said mechanical means or said electric circuit.

12. In a sheet feeder, a frame, sheet separating means arranged to operate on the top sheet of a pile, a main pile support, means on said frame for elevating said support, a pair of hangers one at each side of the pile, supporting means for said hangers above the level of the top of the pile and carried by said frame, said hangers extending downwardly from said supporting means and having ledges below the level of the top of the pile disposed parallel to the direction of sheet feed, means for moving said hangers relatively to bring said ledges into or out of supporting engagement with a pile supporting pallet, whereby said pallet may be withdrawn from said ledges in a direction parallel to the direction of sheet feed for depositing a depleted pile upon a new pile, and means for raising and lowering said hangers relative to said frame independently of said main pile support elevating means.

References Cited in the file of this patent UNITED STATES PATENTS 580,942 Heywood Apr. 20, 1897 2,185,947 Neer Jan. 2, 1940 2,336,839 Blackstone Dec. 14, 1943 2,372,229 Sinkovitz Mar. 27, 1945 2,431,514 Seltzer Nov. 25, 1947 FOREIGN PATENTS 463,495 Great Britain Apr. 1, 1937 595,921 Great Britain Dec. 23, 1947 595,922 Great Britain Dec. 23, 1947 605,424 Great Britain July 22, 1948 

